---
title: HKMetadataKeyDateOfEarliestDataUsedForEstimate
framework: healthkit
role: symbol
role_heading: Global Variable
path: healthkit/hkmetadatakeydateofearliestdatausedforestimate
---

# HKMetadataKeyDateOfEarliestDataUsedForEstimate

The earliest date of data used to calculate the sample’s estimated value.

## Declaration

```swift
let HKMetadataKeyDateOfEarliestDataUsedForEstimate: String
```

## Discussion

Discussion This key takes a Date value, indicating the earliest date from the data used by HealthKit to calculate the sample’s value.